With the 2026 revaluation taking effect on 1 April 2026, business rates are entering a period of major change. But before the new rating list begins, there is one critical deadline that property owners and occupiers cannot afford to ignore:
31 March 2026 is the final date to challenge your current (2023) Rateable Value and reclaim past overpayments.
After this date, you lose the right to backdate corrections, meaning any refunds owed from previous years will be forfeited.
For many commercial property owners, this deadline represents a meaningful financial opportunity.
Why this matters now
If your property has been overvalued on the 2023 rating list, and we routinely find that many are, then you may have been overpaying business rates for up to three years.
Common reasons include:
- Incorrect floor area
- Wrong property classification
- Inaccurate measurement of mezzanines or ancillary space
- Outdated rental evidence
- Changes to the property that were never reported
- Comparables not used correctly by the Valuation Office Agency (VOA)
When these errors are corrected before 31 March 2026, any overpayments already made can be refunded.
When corrected after 31 March 2026, the correction will apply only from April 2026 onwards, meaning the earlier refund is lost.
How the refund works
If a Check/Challenge is submitted in time and the Valuation Office Agency (VOA) agrees that the RV was too high, you may receive:
- A recalculated bill at the correct Rateable Values (RV)
- A refund of the overpaid amounts going back to the date of the error
- Adjusted liability for the remainder of the list
These refunds can be substantial, especially for large commercial premises.
Who should act immediately
You should review your current Rateable Values if you own or occupy:
- Large offices
- Industrial units
- Warehouses, logistics sites, or workshops
- Retail units with fluctuating rental values
- Mixed-use commercial properties
- Empty or part-vacant premises
Even small discrepancies in measurement or classification can produce five-figure differences over a 3-year period.
How Smart Business Tax can help
Our specialist team conducts a property-by-property assessment to identify whether:
- Your RV is overstated
- There are valid grounds for challenge
- A refund is likely
- The VOA’s evidence supports (or fails to support) their valuation
We handle the entire Check/Challenge process on your behalf and ensure cases are submitted before the 31 March 2026 deadline, but only if you act now.
The revaluation coming in April 2026 is important, but for many businesses, the bigger immediate opportunity is reclaiming what has already been overpaid.
Once the 31 March deadline passes, that window closes permanently.
